Flatten PDF — Convert annotations to fixed content

Flattening a PDF converts interactive elements — form fields, annotations, comments, and stamps — into fixed, non-editable content. The result looks identical but no longer contains editable layers.

Use it before sending a filled-in form to ensure the recipient sees the completed version and cannot modify the answers. Also useful for PDFs with comments you want to lock in permanently.

After flattening, the document is lighter and simpler. PDFs with many annotation layers can be surprisingly large, and flattening often reduces their size significantly.